1. Field of the Invention
The present invention relates to electrical interconnects, and more particularly to an interconnect for electrically connecting two conductors separated by some length which repeatedly expands and contracts.
2. Description of the Prior Art
An important source of electrical power for an orbiting satellite is its solar array. In the solar array, an electrical connection is typically made between the solar cell circuits, which convert solar energy into electrical energy, and an electrical wiring harness, which conducts the electrical energy into the spacecraft. Such connections and the substrates to which they are mounted are subject to cyclical, extreme variations in temperature. These variations occur as the satellite orbits the earth. They result from the satellite being in complete sunlight at some times and being in the shadow of the earth at other times. These temperature variations, along with the coefficient of thermal expansion of the substrate, which carries the solar cell circuits and harness, cause a change in distance between those components. Similarly, the unstressed length of the electrical connection, which connects the circuits and the harness, changes, but by a different amount. As the substrate is generally stiffer than the electrical connection, the electrical connection is stressed.
In this regard it has been found that in certain solar arrays the electrical connection failed. Simply put, every hot to cold cycle slightly bent the electrical connection. Eventually, it failed due to mechanical fatigue.
A prior solution to the problem was the use of a conductor in the form of a ribbon electrical interconnect which had a half-loop formed intermediate to its ends to relieve stress. The stress relief improved performance compared to a flat conductor but was found inadequate for spacecraft that had many tens of thousands of repeated movements between the connected points.
What is needed, therefore, is an interconnect for electrically connecting the harness to the solar cell circuits that can accommodate the repeated changes in temperature. An additional requirement in some cases is that the interconnect must be low in height to accommodate the packing requirements for some solar arrays.